Fix for bug 2627 (which was real and not a duplicate).

blocks/db/mysql.php

@@ -126,6 +126,10 @@ global $CFG;
         $result = $result && table_column('block_instance', 'position', 'position', 'varchar', '10', '');
     }
 
+    if ($oldversion < 2004112900 && $result) {
+        execute_sql('UPDATE '.$CFG->prefix.'block_instance SET pagetype = \''.PAGE_COURSE_VIEW.'\' WHERE pagetype = \'\'');
+    }
+
     //Finally, return result
     return $result;
 }

blocks/version.php

@@ -5,4 +5,4 @@
 // database (blocks_version) to determine whether upgrades should
 // be performed (see db/backup_*.php)
 
-$blocks_version = 2004111200;   // The current version is a date (YYYYMMDDXX)
+$blocks_version = 2005022400;   // The current version is a date (YYYYMMDDXX)